Spence said he was ''gutted'' to have to make that decision, but economics meant he could no longer afford to slaughter pigs at his boutique abattoir.
The change would bring to an end 50 years of pig processing for Spence (74), since he set out doing farm kill in Kaitangata in 1969.
''We've averaged probably seven or eight hundred pigs a year, dropping off a bit now I'm semi-retired. It's about a third of my turnover, so pretty significant.''
South Kill would continue to process sheep, but pigs had been a ''way of life'' for him and his family, he said.
''We brought our kids up and bought our house on it. They'd help slice the bacon and so on. When you've done it for so many years you feel something's been cut out from under you.''
He said practitioners would now have to dispose of pig offal through costly landfill processing, or in offal pits if slaughtering on farm, where offal was required to be retained.
''I just feel for my lifestyle customers, who fatten a single pig and use it to feed the family.''
Milton butcher Tiny Agnew, who co-operates with Spence in processing his customer's pig carcasses, and also runs his own farm kill operation, said the lapse in offal collection would cause problems for all Southern practitioners.
''We understand Keep It Clean's decision, but locally we'll take a revenue hit due to South Kill's step back, as we don't do pig slaughter ourselves.
''There'll also be a few of the bigger operations down south with hard decisions to make. When reality hits there'll be a bit of a panic, I think.''
He believed increased processing costs would ultimately fall on the consumer.
''We'll have to see how it plays out.''
Wallace Group's spokesman said the change could require the attention of local government.
''It's unfortunate, but as well as increased charges for consumers, disposal could become a problem for the environment. I suspect councils will need to take a look at landfill provision moving forward.''